RM0033 Rev 9 765/1381
RM0033 Secure digital input/output interface (SDIO)
791
ERASE_TIMEOUT
This 6-bit field indicates TERASE and the value indicates the erase timeout from offset
when multiple AUs are being erased as specified by ERASE_SIZE. The range of
ERASE_TIMEOUT can be defined as up to 63 seconds and the card manufacturer can
choose any combination of ERASE_SIZE and ERASE_TIMEOUT depending on the
implementation. Determining ERASE_TIMEOUT determines the ERASE_SIZE.
ERASE_OFFSET
This 2-bit field indicates TOFFSET and one of four values can be selected. This field is
meaningless if the ERASE_SIZE and ERASE_TIMEOUT fields are set to 0.
26.4.13 SD I/O mode
SD I/O interrupts
To allow the SD I/O card to interrupt the MultiMediaCard/SD module, an interrupt function is
available on a pin on the SD interface. Pin 8, used as SDIO_D1 when operating in the 4-bit
SD mode, signals the cards interrupt to the MultiMediaCard/SD module. The use of the
interrupt is optional for each card or function within a card. The SD I/O interrupt is level-
sensitive, which means that the interrupt line must be held active (low) until it is either
recognized and acted upon by the MultiMediaCard/SD module or deasserted due to the end
of the interrupt period. After the MultiMediaCard/SD module has serviced the interrupt, the
interrupt status bit is cleared via an I/O write to the appropriate bit in the SD I/O card’s
internal registers. The interrupt output of all SD I/O cards is active low and the application
must provide external pull-up resistors on all data lines (SDIO_D[3:0]). The
MultiMediaCard/SD module samples the level of pin 8 (SDIO_D/IRQ) into the interrupt
detector only during the interrupt period. At all other times, the MultiMediaCard/SD module
ignores this value.
Table 118. Erase timeout field
ERASE_TIMEOUT Value definition
00 Erase timeout calculation is not supported.
01 1 [sec]
02 2 [sec]
03 3 [sec]
--------- ---------
63 63 [sec]
Table 119. Erase offset field
ERASE_OFFSET Value definition
0h 0 [sec]
1h 1 [sec]
2h 2 [sec]
3h 3 [sec]
To Next Page
Loading...
Need help?
General
